Sheets comprising filaments of fungi



SHEETS COMPRISING FILAMENTS OF FUNGI 2,81 1,442 F atented Oct. 29, 1957Sheets comprised of mycellia alone and dried in the air or by dry heattend to become brittle. We have found, however, that the addition ofsmall amounts of cellulose fiber, which in effect, provides aplasticizer,

ng Van Ham and Bernard E Shema, Appleton, 5 permits the manufacture of avery satisfactory sheet.

Wis, William H. Shockley, Camas, Wash., and Julian H. Conkey, Appleton,Wis., assignors to The Institute of Paper Chemistry, Appleton, Wis., acorporation of Wisconsin N Drawing. Application April 12, 1954, SerialNo. 422,652

12 Claims. (C1 92 -3) The present invention relates generally to the useof mycelium in the manufacture of sheets and it also relates to the useof mycelium in the manufacture of paper.

In order to have a clear understanding of the invention and in view ofsome disagreement among botanists as to terminology, it is necessary todetail some of the general background of the invention. As is wellknown, life on earth may be considered to be divided between the animaland the plant kingdoms. Within the plant kindom, there are included twophyla, one being known as Sperma-tophyta and the other being known asThallophyta.

The Spermatophyta embraces the highest plants, or those that produceseeds, such as trees. It is from this phylum of the plant kingdom thatpaper and paper products, as we know them today, are made. Sirchproducts are produced from the sclerenchy'ma which includes, in the caseof trees, fibers. The fibers, in the course of paper making, aregenerally matted or felted together to provide a sheet. The presentinvention is not directed to this phylum of the plant kingdom.

The Tha-llophyta are arather diverse group of plants and for purposes ofthis specification are considered to include fungi, algae, bacteria,lichens and slirn'e molds. Since the present application relatesprimarily to fungi, the other divisions of Thallophyta are mentioned forclassification purposes.

Fungi, by definition, include plants which do not contain chlorophyl andare typically saprophytic and/or parasitic in nature; these fungireprodu'ce sexually and asexually through spores developed in variousways. Fungi comprise the classes of Phycornycetes, Ascomycetes andBasidiomycetes. For purposes of this specification, fungi also includeFungi Imperfecti and, it should be understood that they further includethe Schi zomycet'es' (bacteria) and Myxornycetes (slime molds).

While the structures of fungi vary considerably, thethallus may befilamentous in character. On the other hand, the thallus may benon-filamentous in structure. The mycelium is the filamentous portion ofthe thallus of fungi, as used in this specification; and consists of amass of interwoven hyphae.

The principal object of the present invention is the provision of amethod of manufacture of filamentous fungi and to provide new materialscomprising. such fungi. This and other objects of the invention may beaccomplished through growing fungi under controlled conditions orrecovering substantially pure filaments of fungi from nature, andmanufacturing such fungi into sheets or utilizing them in themanufacture of paper and paper products having improved properties.

In the practice of the present invention, substantially pure filamentsof fungi are prepared and disintegrated in substantially the same manneras in the manufacture of paper. The disintegrated fungi may be suspendedin water and then made into a sheet;- In'a'ddition, the fungi may becombined with cellulose fibers which are then made into a sheet.

. innit squarecopper rods and extending from a pointctie The amount ofcellulose fiber can be varied to provide the desired amount ofpliability.

A sheet fabricated from mycelia, with as little as ten percent, byweight, cellulose fibers, has unusual flexibility and, while sheetswhich have so far been made have somewhat less strength than comparablepaper sheets, the characteristics of the sheet are much the same.Furthermore, when the sheet is subjected to heat or pressure, or both, acontinuous film is formed which is both transparent and flexible. Papersheets including the mycelia have high gloss and good printingcharacteristics which makes the mycelia valuable as a sizing agent.Furthermore, the addition of mycelia to wood pulp makes possible themanufacture of paper and paper products having flame resistantproperties.

It will be seen from the foregoing that we have not only provided awholly new product but also have provided a product for improving thecharacteristics of aper.

While various media may be employed for growing the mycelia, certainconditions are preferably followed to provide mycelia having the desiredcharacteristics. To illustrate the manner of growing the myce'lia, aparticular medium is disclosed. The medium should be sterile topr'eventformation of undesired Thallophyta or other phylum. The particularmedium used comprised 1000 milliliters of tap Water; 20 grams ofdextrose; 3.0 grams of ammonium nitrate; 3.0 grams of potassiumhydrogenphosphate; .25 gram of potassium chloride; .25 gram of hydratedmagnesium sulfate (MgSOrr-7H20'); .O l' gram of Zinc sulfate; and 5.0grams of glycerine. The medium was placed in a sterile container andsterile air was diffused through it. The medium was inoculated with aPh'ycom-ycetes of the order Mucoral'e's.

The air was diffused through the medium for about 70 hours, thetemperature being maintained between F. and F. At the end of this time ayield of 5 grams (dry basis) per liter of medium was obtained.

It is of substantial importance that the air be continuously diffusedthrough the medium at such a rate during growth as to maintain themyce'lium in a filamentous cond-itiona In one run, the air was diffusedin four liters of the medium in a six liter bottle at the rate of 2 to 8cubic feet per minute at standard temperature-pressure conditions.

After the filaments have" been produced in the medium, they are filteredor'centrifuged out, and washed with water and may then be washed with a'mild acid or mild alkaline solution, following which, they may be thenagain washed with water. The filaments may be boiled or left unboiled. I

Following washing; the myceli'umis placed in a beating machine ordisinte'grat'or and Water added to make up a two to five percentmyceliummixture. The mycelium is thendisintegratedt The degree ofdisintegration is dl fii cult to specify but it is carried out to thepoint where a good'sheet may be produced. In this connection, the dilutemixture of myceliumwas placed in a TAlPI stand ard disintegrator andbeaten for about forty seconds at 3000' R. P.

The-TAPPI disin-t'egrat'or comprises a container in which,

is disposed a propeller. The container is cylindrical in shape and hasadiameter measuring six inches. In height the container measures sevenand one-half inches. Fo'u spiral baflies are attached to the inside wallof, the con tainer; the; baiii'es Being manufactured from one-quarto andone-quarter inches from the bottom of the container to a point two andone-quarter inches from the top of the container. Each baffie spiralsaround one-half of the circumference of the container.

The propeller of the disintegrator is built up from three hard brassblades set 120 degrees apart. In diameter, the propeller measures aboutthree and one-half inches and the propeller is one inch from the bottomof the container. The blades slope 2 degrees upwardly to thereby throwthe stock downwardly. A suitable motor and drive mechanism is providedfor rotating the blades at 3000 R. P. M.

After disintegration, the mycelium mixture is further diluted to aone-half to three-quarter percent mixture and passed through aFourdrinier wire to make what is known as a hand sheet. This is done inaccordance with well known practices.

The sheet may be subjected to heat and pressure thereby becomingpractically transparent. In this connection, when the sheet is subjectedto 250 pounds per square inch and a temperature of 240 degreesFahrenheit, for ten minutes, the transparent character becomes apparent.It appears from this that the mycelia may be thermoplastic in nature.The amount of heat and/ or pressure required may be readily determinedby tests to provide the degree of transparency desired.

In order to give mycelia sheets improved flexibility, a plasticizingagent should be added. In this connection, wood pulp provides anexcellent plasticizer. We have found that when ten percent wood pulp isadded to the mycelia, the resulting sheet has good pliability.

Sheets made from mycelia and from a combination mycelia and wood pulphave good flame resistance when compared to paper. In this connection,the sheets will not sustain a flame. Furthermore, the sheets have goodwriting and printing properties.

In addition, sheets of mycelia with small amounts of wood fiber havecomparable bursting strength to that of sheets made with wood fiber.When a mycelium sheet was prepared with Mucorales and about sevenpercent bleached jack pine kraft fibers, and compared with a sheetcontaining one hundred percent of such fibers, the bursting strength, bythe Mullen test, of the mycelium sheet was only slightly less than thatof the paper sheet.

The mycelia sheets also have a comparable tensile strength to papersheets, when wet or dry. However, the mycelia sheets have substantiallyincreased stretch when compared to fiber sheets. in this connection,when the above described sheets were compared, the mycelium sheet hadapproximately four times the stretch of the paper sheet.

While the mycelia may be used to provide a sheet having many desirablequalities, it may be also employed in paper manufacture as a sizingagent and to improve wet strength. Thus, the mycelia may be added towood pulp in varying amounts to provide a sheet, in a normal papermanufacturing operation which includes calendaring or other heat orpressure conditions, having high gloss. This characteristic occurs eventhough other plasticizers, such as glycerine, are added. As indicated,addition of mycelia also appears to improve the Wet strength of thepaper. It has been found that high gloss and increased wet strength areprovided by the addition of ten percent mycelia.

As pointed out, this invention is directed to the use of mycelia of thePhycomycetes, Ascomycetes, Basidiomycetes, and Fungi Imperfecti classes,and the filamentous forms of Myxomycetes and Schizomycetes. However, wehave obtained most satisfactory results from mycelia in the Phycomycetesclass and, insofar as our experiments have gone, the Mucorales typeappears to give best results.

While the mycelia may be obtained from various natural fungi such asaquatic fungi, mushrooms, conks, etc., we have found it quite difficultto purify and separate out the mycelia. Accordingly, it appearsnecessary to artificially prepare the mycelium. In addition, suchartificial preparation seems to be the most economical way of preparingthe mycelia. In this connection and as pointed out above, throughartificial production of the mycelia, the filamentous conditionmay bemaintained so as to thereby make possible higher yields.

It will be apparent from the foregoing that we have provided a whollynew type of sheet which is made from a material which has heretoforebeen considered to be largely valueless. In addition, the product hasbeen found to provide certain desired properties to paper when used inconnection with the manufacture of paper.

The various features of our invention, which are believed to be new, areset forth in the following claims.

We claim:

1. A hi hly flexible, high gloss sheet having writing and printingproperties similar to paper sheets comprising filaments of fungi inamounts in excess of about 10 percent of the weight of the sheet, theremaining portion of said sheet comprising papermaking fibers.

2. A highly flexible, high gloss sheet having writing and printingproperties similar to paper sheets comprising mycelia from thePhycomycetes class in amounts in excess of about 10 percent of theweight of the sheet, the remaining portion of said sheet comprisingpapermaiting fibers.

3. A highly flexible, high gloss sheet having writing and printingproperties similar to paper sheets comprising mycelia from the Mucoralesorder of Phycomycetes in amounts in excess of about 10 percent of theweight of the sheet, the remaining portion of said sheet comprisingpapermaking fibers.

4. A highly flexible, high gloss sheet, having writing and printingproperties similar to paper sheets, consisting of filaments of fungi.

5. A highly flexible, high gloss sheet having writing and printingproperties similar to paper sheets comprising mycelia and wood fibers,the mycelia comprising in excess of about 10 percent of the weight ofthe sheet, the remaining portion of said sheet comprising wood fibers.

6. A highly flexible, substantially transparent sheet having writing andprinting properties of paper sheets comprising mycelia, the myceliacomprising in excess of about percent of the weight of the sheet, andless than 10 percent wood fibers.

7. A highly flexible, high gloss paper sheet including filaments offungi, the fungi comprising at least 10 percent of the weight of thesheet, the remaining portion of said sheet comprising papermakingfibers.

8. A highly flexible, high gloss paper sheet including mycelia from theMucorales order of Phycomycetes, the mycelia comprising in excess of 10percent of the weight of the sheet, the remaining portion of said sheetcomprising papermaking fibers.

9. A highly flexible, substantially transparent sheet, having writingand printing properties similar to paper sheets, comprising more thanabout 90 percent mycelia of the Phycomycetes class and papermakingfibers.

10. A highly flexible, high gloss sheet having writing and printingproperties similar to paper sheets comprising mycelia from theBasidiomycetes class in amounts in excess of about 10 percent of theweight of the sheet, the remaining portion of said sheet comprisingpapermaking fibers.

11. A highly flexible, high gloss sheet having writing and printingproperties similar to paper sheets comprising mycelia from theAscomycetes class in amounts in excess of about 10 percent of the weightof the sheet, the remaining portion of said sheet comprising papermakingfibers.

12. A highly flexible, high gloss sheet having writing and printingproperties similar to paper sheets comprising mycelia from the FungiImperfecti class in amounts in excess of about 10 percent of the weightof the sheet,

the remaining portion of said sheet comprising paper- 2,578,695 7 makingfibers. 2,596,969 2,600,504 References Cited in the file of this patent2,654,671 UNITED STATES PATENTS 5 2,698,307

717,274 Reardon Dec. 30, 1902 1,708,586 Millington Apr. 9, 19292,480,851 Goss Sept. 6, 1949 2,485,587 Goss Oct. 25, 1949 10 2,564,889Folkers Aug. 21, 1951 2,571,693 Dulaney Oct. 16, 1951 6 Goss Dec. 18,1951 Hendin May 20, 1952 Leeds et a1. June 17, 1952 Azorlosa Oct. 6,1953 Heritage Dec. 28, 1954 OTHER REFERENCES Antibiotics, vol. H, p.721, published by Oxford University Press, New York (1949).

Gadd, Institute of Paper Chemistry Bulletin, vol. 21, p. 620, May 1951.

1. A HIGHLY FLEXIBLE, HIGH GLOSS SHEET HAVING WRITING AND PRINTINGPROPERTIES SIMILAR TO PAPER SHEETS COMPRISINGNG FILAMENTS OF FUNGI INAMOUNTS IN EXCESS OF ABOUT 10 PERCENT OF THE WEIGHT OF THE SHEET,THEREMAINING PORTION OF SAID SHEET COMPRISING PAPERMAKING FIBERS.